iOS Mapkit 注释无法拖动

Question

我是 iOS 开发的新手，我需要在 iOS 地图中实现可拖动注释。我的代码给出了 below.whater 我曾经做过我无法获得可拖动的注释任何人都可以帮助处理注释之后我需要获取图钉指向的位置的地址

RegistrationViewController.swift

class RegistrationViewController: UIViewController,UIPickerViewDelegate,UIPickerViewDataSource,MKMapViewDelegate{
    @IBOutlet weak var mapView: MKMapView!

    override func viewDidLoad() {
        super.viewDidLoad()
        var centerLocation = CLLocationCoordinate2DMake(12.964370125970357, 77.59643554937497)
        var mapspan = MKCoordinateSpanMake(0.01, 0.01)
        var mapregion = MKCoordinateRegionMake(centerLocation, mapspan)
        self.mapView.setRegion(mapregion, animated: true)

        let pin = pinAnnotation(title:"hello",subtitle:"how are you",coordinate:centerLocation)
        mapView.addAnnotation(pin)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {
        if annotation is MKPointAnnotation {
            let pinAnnotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: "myPin")
            pinAnnotationView.pinColor = .purple
            pinAnnotationView.isDraggable = true
            pinAnnotationView.canShowCallout = true
            pinAnnotationView.animatesDrop = true

            return pinAnnotationView
        }

        return nil
    }

    func mapView(_ mapView: MKMapView, annotationView view: MKAnnotationView, didChange newState: MKAnnotationViewDragState, fromOldState oldState: MKAnnotationViewDragState) {
        switch newState {
        case .starting:
            view.dragState = .dragging
        case .ending, .canceling:
            view.dragState = .none
        default: break
        }
    }

pinAnnotation.swift

import MapKit

class pinAnnotation:NSObject,MKAnnotation {
    var title:String?
    var subtitle: String?
    var coordinate: CLLocationCoordinate2D
    init(title:String,subtitle:String,coordinate:CLLocationCoordinate2D) {
        self.title = title
        self.subtitle = subtitle
        self.coordinate = coordinate
    }
}

Answer 1

您已通过将 isDraggable 属性设置为 true 完成了第一步。现在你只需要在用户停止拖放注释时处理，参见： how to manage drag and drop for MKAnnotationView on IOS

此外，您的 pinAnnotation 应该有一个可设置的坐标。

来自Apple documentation：

Marking Your Annotation View as Draggable Annotation views provide built-in dragging support, which makes it very easy to drag annotations around the map and to ensure that the annotation data is updated accordingly. To implement minimal support for dragging:

In your annotation objects, implement the setCoordinate: method to allow the map view to update the annotation’s coordinate point. When creating your annotation view, set its draggable property to YES. When the user touches and holds a draggable annotation view, the map view begins a drag operation for it. As the drag operation progresses, the map view calls the mapView:annotationView:didChangeDragState:fromOldState: method of its delegate to notify it of changes to the drag state of your view. You can use this method to affect or respond to the drag operation.

To animate your view during a drag operation, implement a custom dragState method in your annotation view. As the map view processes drag-related touch events, it updates the dragState property of the affected annotation view. Implementing a custom dragState method gives you a chance to intercept these changes and perform additional actions, such as animating the appearance of your view. For example, the MKPinAnnotationView class raises the pin off the map when a drag operation starts and drops the pin back down on the map when it ends.

您缺少 mapView:annotationView:didChangeDragState:fromOldState: 方法

Answer 2

在你的情况下 annotation 不是 MKPointAnnotation 类型。这就是为什么它没有进入 if annotation is MKPointAnnotation { 条件。

应该是这样的：

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {

    if annotation is pinAnnotation {

        let pinAnnotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: "myPin")
        pinAnnotationView.pinTintColor = .purple
        pinAnnotationView.isDraggable = true
        pinAnnotationView.canShowCallout = true
        pinAnnotationView.animatesDrop = true

        return pinAnnotationView
    }

    return nil
}

因为annotation是pinAnnotation类型。

我在你的代码中看不到 mapView.delegate = self。但是，如果您通过情节提要分配它，那很好，否则将其添加到 viewDidLoad 方法中。

你的完整代码将是：

import UIKit
import MapKit

class ViewController: UIViewController,MKMapViewDelegate{
    @IBOutlet weak var mapView: MKMapView!


    override func viewDidLoad() {
        super.viewDidLoad()
        mapView.delegate  = self
        let centerLocation = CLLocationCoordinate2D(latitude: 12.964370125970357, longitude: 77.59643554937497)
        let mapspan = MKCoordinateSpanMake(0.01, 0.01)
        let mapregion = MKCoordinateRegionMake(centerLocation, mapspan)
        self.mapView.setRegion(mapregion, animated: true)

        let pin = pinAnnotation(title:"hello",subtitle:"how are you",coordinate:centerLocation)
        mapView.addAnnotation(pin)

    }


    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {

        if annotation is pinAnnotation {

            let pinAnnotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: "myPin")
            pinAnnotationView.pinTintColor = .purple
            pinAnnotationView.isDraggable = true
            pinAnnotationView.canShowCallout = true
            pinAnnotationView.animatesDrop = true

            return pinAnnotationView
        }

        return nil
    }

    func mapView(_ mapView: MKMapView, annotationView view: MKAnnotationView, didChange newState: MKAnnotationViewDragState, fromOldState oldState: MKAnnotationViewDragState) {
        switch newState {
        case .starting:
            view.dragState = .dragging
        case .ending, .canceling:
            view.dragState = .none
        default: break
        }
    }
}

编辑

您可以通过 view.annotation?.coordinate

获取新位置

检查下面的代码：

func mapView(_ mapView: MKMapView, annotationView view: MKAnnotationView, didChange newState: MKAnnotationViewDragState, fromOldState oldState: MKAnnotationViewDragState) {
    switch newState {
    case .starting:
        view.dragState = .dragging
    case .ending, .canceling:
        //New cordinates
        print(view.annotation?.coordinate)
        view.dragState = .none
    default: break
    }
}

iOS Mapkit 注释无法拖动

iOS Mapkit Annotation is not getting draggable

mapkit

mkannotation

ios

swift